Newton's Second Law of Motion

What does Newton’s second law of motion say?

When dealing with an object for which all existing forces are not balanced, the acceleration of that object(as produced by net force) is in the same direction as the net force and directly proportional to the magnitude of the net force, and is inversely proportional to the objects mass.

What is the formula for Newton’s second law of motion?

Acceleration= Force/Mass (A=F/M)

What is the formula to figure out force?

Force= Mass x Acceleration ( F=MA)

The greater an object’s mass, the greater:

The force you need to overcome it’s inertia, which is described in Newton’s first law of motion.

Why is starting or stopping a moving 50 car train carrying lead a lot harder than starting or stopping a toy car in motion?

Because the force necessary to overcome an object’s inertia is inversely proportional to its mass.